This invention relates to rotary braiding machines, and particularly to rotary wire-braiding machines of the type used in making braided-wire high-pressure hose.
In a typical rotary braiding machine, a pair of concentric coaxial plates or tables each carry a set of bobbins. The tables are rotated along circular paths in opposite directions about the center axis of the machine. A central cord or mandrel projects forwardly through a forward opening located on the center axis of the machine. The strands carried by the bobbins are drawn forwardly along convergent lines which come together just forward of the opening. The strands are interlaced or braided at the point of convergence about the center cord or mandrel. As the strands are pulled forwardly, they are drawn over the edge of a forwardly projecting stationary cylinder located on the center axis of the machine. Since the strands of the one set of bobbins are moving along a circular path in a direction opposite to that of the strands of the other set of bobbins, the strands of one set bear against the strands of the other set as they cross and this interference may result in a lack of uniformity which shows up as an imperfection in the braiding pattern.
The problem briefly described above was recognized by the prior art in U.S. Pat. No. 1,976,931 which issued to B. K. Ford on Oct. 16, 1934. In the Ford patent, a transverse slot having serrated edges is provided in the rotationally stationary cylinder over the forward edge of which the strands are drawn. A cam roller, secured to the rotational braider head, passes through the slot and causes the rotationally stationary cylinder to be moved reciprocatingly in the axial direction due to the engagement between the cam roller and the peaks of the serrations. This arrangement does not, however, permit the timing of the reciprocations to the crossings, nor the adjustment of the axial stroke, relative to the braid strand configuration which extends from the stationary guide cylinder to the braid point. This configuration changes with the specifications of the product being produced.
It is also believed that the prior art was intended to "beat" the braid formation off of a forming sleeve thereby slipping the formed braid on to the product. In contrast thereto, the present invention is directed to a mechanism in which the yarn or wire strands are braided right on the product which, in the case of wire braiding, may be a high pressure hose having a hollow rubber or fabric core.